Task Portugal
From: “Prior Stuart” <Stuart.Prior@leicestershire.pnn.police.uk>
To: “Task Portugal” <Task.Portugal@leicestershire.pnn.police.uk>
Sent: 04 September 2007 10:14
Subject: FW: Op Task – in Confidence
From: Lowe, Mr J R [mailto:John.Lowe@fss.pnn.police.uk
Sent: 03 September 2007 15:01
To: stuart.prior@leicestershire.pnn.police.uk
Subject: Op Task – In Confidence
Stuart
Firstly, here are the last three results you are expecting
An incomplete DNA result was obtained from cellular material on the swab 3a. The swab contained very little information and showed low level indications of DNA from more than one person. However, all of the confirmed DNA components within this result match the corresponding components in the DNA profile of Madeline McCann. LCN DNA profiling is highly sensitive it is not possible to attribute this DNA profile to a particular body fluid.
There is no evidence to support the view that Madeline MCCann contributed DNA to the swab 3B.
A complex LCN DNA result which appeared to have originated from at least three people was obtained from cellular material recovered from the luggage compartment section 286C 2007 CRL10 (2) area 2. Within the DNA profile of Madeline McCann there are 20 DNA components represented by 19 peaks on a chart. At one of the areas of DNA we routinely examine Madeleine has inherited the same DNA component from both parents; this appears therefore as 1 peak rather than 2, hence 19 rather than 20. Of these 19 components 15 are present within the result from this item; there are 37 components in total. There are 37 components because there are at least 3 contributors; but there could be up to five contributors. In my opinion therefore this result is too complex for meaningful interpretation/inclusion.
Why – …
Well lets look at the question that is being asked
“Is there DNA from Madeline on the swab “
It would be very simple to say “yes” simply because of the number of components within the result that are also in her reference sample.
What we need to consider, as scientists, is whether the match is genuine and legitimate; because Madeline has deposited DNA as a result of being in the car or whether Madeline merely appears to match the result by chance. The individual components in Madeline’s profile are not unique to her, it is the specific combination of 19 components that makes her profile unique above all others. Elements of Madeline’s profile are also present within the the profiles of many of the scientists here in Birmingham, myself included. it’s important to stress that 50% of Madeline’s profile will be shared with each parent. It is not possible in a mixture of more than two people, to determine or evaluate which specific DNA components pair with each other. Namely, we cannot separate the components out into 3 individual DNA profiles.
Therefore, we cannot answer the question: is the match genuine or is it a chance match.
The same applies to any result that is quoted as being too complex for meaningful inclusion/interpretation
What questions will we never be able to answer with LCN DNA profiling –
When was the DNA deposited –
How was the DNA deposited –
What body fluid(s) does the DIVA originate from –
Was a crime committed –
These, along with all other results, will be formalised in a final report
Please don’t hesitate to contact me if you require any further assistance
kind regards
John
John Lowe Forensic Scientist
Major Incidents Team
Priory House
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